Printrun

In real life TCGs, the cards are printed out in a certain order on big cardboard sheets, which are cut up and sent into hoppers and then distributed to booster packs. It means that rather than getting a completely random distribution of cards in each pack, you get a more sensible spread, which is especially important in draft. (In truly random cases, for instance, you could get a booster with all Wild cards in (terrible for Draft); printruns stop that from happening.)

To ensure different content of packs Hex will emulate printruns of TCG's.

Reference: Cory Jones interview, 2013-june-05